I've successfully managed to boot Debian installer (supplied the installation disc's initrd.gz); however, it is unable to mount the CD image itself, although I have enabled it in the DomU configuration like this:

The problem is that we need to teach students installing Debian; at the same time, we have no spare computers that can be completely be given into their possession. That's why we use Xen, and that's why we need to make the installer work, not just provide them debootstrapped systems.
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dpqFeb 17 '10 at 13:00